The fix for 4396541 appears to have completely broken Jini multicast on Windows. Jini relies on being able to open multiple MulticastSockets on the same port on the same host, so use of SO_REUSEADDR is mandatory. The current code appears to unilaterally disallow this on 95/98/ME, and requires a possible SP upgrade and an administrator to edit the registry on NT and 2K. This is an unacceptable regression from earlier releases that puts Jini dead in the water on merlin.